Scott Disick is seeking treatment for alcohol and substance abuse.

PEOPLE Magazine has reported that the reality star and father to Kourtney Kardashian's children has checked himself into Cliffside Malibu, a luxury drug and alcohol rehabilitation centre.

A source told the publication that Scott, 32, decided to seek help after Kourtney, 36, gave him an ultimatum about being able to see kids Mason, 5, Penelope, 3, and Reign, 10 months.

"He wants to make it stick this time because he has come close to losing everything," the source revealed.

The news comes as scott's friend and Khloe Kardashian's ex-husband Lamar was hospitalisation, after being found unconscious at a Nevada Brothel.

However, the source added that Scott made the decision to check into rehab before the incident with Lamar, revealing he most likely doesn't know about the NBA star's critical condition.

"They don't want it to interfere with his progress."

Following their split in July, Kourtney planned to seek sole custody of the pair's three children as "she thinks he is a drunk mess."

Kourtney and Scott's relationship woes have long been a sore subject, with the couple finally breaking up after he was seen getting close to stylist Chloe Bartoli in Monte Carlo.

A friend of Scott's told PEOPLE that his alcohol and drug use took a turn for the worse after the death of both his parents.

"He took it incredibly hard and was in a very dark place after it happened," the insider shared.

"Scott insisted his drinking is under control, that he's not in a spiral, but everyone around him knows the truth. He has been lying to everyone, saying that he's clean and sober....and he insists that he doesn't have a problem."

Here's hoping his fourth stint in rehab will do the trick. Scott's problems were creating "a poor environment for her kids to be raised in," the source contiued. "Her children are her first priority."